Only a few studies, mainly qualitative thematic analyses of interviews, have dealt with the psychological experience of parents of children and adolescents with osteogenesis imperfecta (OI), a rare genetic syndrome involving skeletal fragility and increased exposure to bone fractures. The aim of the present study was to evaluate both negative (i.e., parental burden and parenting stress) and positive (i.e., coping strategies and perceived social support) experiences of parents related to their children's disease and behaviour. The participants were 34 parents of children and adolescents with OI who completed a specifically developed online survey assessing their psychological experience with caregiving, their perception of the severity level of their children's condition and any possible behavioural problems experienced by their children. Data analyses showed that 65% of the parents showed a clinical level of caregiver burden and nearly 30% a clinical level of parenting stress. Caregiver burden was related to the perceived severity level of the condition and the externalising problems shown by their children. Concerning the positive aspects of the parents' experience, a high level of perceived social support was connected to a lower level of parenting stress; the same did not happen for caregiver burden. Coping strategies were connected to stress and burden; in particular, a higher level of stress corresponded to a higher level of avoidance, and a higher level of burden corresponded to a higher level of positive attitude.